Telephone-exchange apparatus



(No Model.) Y 2 Sheets-Sheet 1. J. J. GARTY. TELEPHONE EXCHANGE APPARATUS.

P'a'tentedMay 6, 1890.

MAHA- fax/5:22 :11 AIME,czzrmiv A (No Model. a 2 Sheets-Sheet 2. J. J. GARTY.

TELEPHONE EXCHANGE APPARATUS.

No. 427,156. Patented May 6', 1890-;

Clockwork box.

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UNITED STATES PATENT OFFICE.

JOHN J. CARTY, OF NEW YORK, N. Y., ASSIGNOR TO THE WESTERN ELECTRIC COMPANY, OF CHICAGO, ILLINOIS.

TELEPHONE-EXCHANGE APPARATUS.

SPECIFICATION forming part of Letters Patent No. 427,156, dated May 6, 1890.

Application filed October 26, 1889. Serial No. 328,290. (No model.)

To all whom it may concern: the central office in connection with each tele- Be it known that I, JOHN J. OARTY, a citizen phone-line a different relay, these relays beof the United States, residing at New York, ing arranged so that when current is sent in the county of New York and State of New through any one of them its armature will be York, have invented a certain new and usebrought into the path of a moving circuitful Improvement in Telephone-Exchange Apcloser, this circuit-closer serving to complete paratus, (Case 9,) of which the following is a the connection with the operators telephone; full, clear, concise, and exact description, refsecond, in providing at each station a diiferenerence being had to the accompanying drawtially-wound telephone and a diiferentially- 1o ings, forming a part of this specification. wound inductorium,the diiferent sides of the Heretofore in telephone-exchange systems metallic circuit including each a diiferent pormeans have been provided whereby any subtion or section of the differential windings, scriber could bring his telephone into circuit and one coil of a converter at the central with the telephone of a listening operator at office, a branch from said coil through the 15 the central office, so as to give his orders dispecial relay of the line, and thence through rect. This system has not been very generally a battery to ground, together with a key at used, one of its great objections being the the subscribers station 3 for completing a confusion resulting when several impatient ground-circuit from the center of the differsubscribers attempt to simultaneously give ential winding of the telephone to ground;

20 orders to the same listening operator. As third, in a rotating arm driven by clockshown in Reissue Letters Patent No. 10,989, work or other suitable means, and aseries of granted WVilliam B. Vansize March 5, 1889, relays with their armatures normally out of for telephone-exchange, it has been attempted the path of said revolving arm, but in such to avoid this difficulty by providing a rotatrelation thereto that when any armature is 2 5 ing arm at the central station adapted to make attracted it will be brought into the path of 7 5 and break connection with the different conthe arm to arrest the same and hold it in posiductors of the different subscribers succestion until the armature is retracted, and, sively and periodically, the circuits being so fourth, in a circuit containing the listeningarranged that a subscriber may at the mooperators telephone connected with a re- 0 ment when connection is made with his line volving arm, said arm being adapted to be ararrest the movement of the rotating arm, and rested by the armature of arelay to close conthus bring his telephone into connection with tact with said armature, said armature being the telephone of the listening-operators line. connected through a coil of a converter to All other telephone-lines will be disconnected ground, the other coil of said converter being 3 5 therefrom. included in a metallic-circuit telephone-line,

The invention as described in said patent whereby said telephone-line is connected teleis adapted for use in connection with single phonically' with the circuit containing the or grounded circuit telephone-lines,andis not listening-operators telephone. well adapted for use in connection with any My invention is illustrated in the accom- 40 of the metallic-circuit systems with which I panying drawings, in which am familiar. Figure 1 is a diagram illustrative of three The object of my invention is to provide metallic-circuit telephone-lines, each being means whereby the different subscribers may connected through the winding of a different connect themselves one at a time with the converter at the central office,the otherwind- 45 listening operator, my invention being espeing of each of said converters including a cially adapted for use in connection with mewire extending each to a different switch on tallic-cirouit systems when used in multiplethree difierent switch-boards, together with switch-board systems or in systems employthe operators outfit at one of the boards, the ing single switch-boards. moving arm in connection with the relays of 50 My invention consists, first, in providing at the different telephone-lines and the sub- I00 scribers apparatus at one station in detail. Fig. 2 is a side elevation of a relay and the moving arm.

Referring now to Fig. 1, it will be seen that the telephone a at subscribers station 1 is wound differentially. The different oppos'ite windings of the telephone are extended to the inductorium b and wound about the same each oppositely. The telephone-line or metallic circuit 0 includes in different sides thereof these differential windings, and at the central office includes a winding of the converter d. A. branch 6 .from this coil of the converter extends through the coil of the relay f, and thence through a source of electricity to ground. The other coil of the converter is included in a circuit g, extending to a switch on each of the multiple switchboards 1 2 3, and is normally open in this direction, the end of wire 9 on the other side of the converter being grounded. A branch 7; from the open side of wire 9 extends to the armature of relay f.

The operators telephone 2' is included in a circuit connecting with the revolving arm 70. This arm is driven, preferably, by clockwork and preferably rotated, so as to pass near the armatures of the different relays one after another, without, however, coming in contact with any one of them except when an armature is actuated.

At the subscribers station is provided a key 1, adapted to close upon a contact m at the center of the differential winding of the telephone.

I have not deemed it necessary to describe in detail the manner of making the connec* tions and disconnections between the telephone-lines upon the switch-board, since my invention relates more particularly to the instrumentalities whereby any subscriber is enabled to puthimself into telephonic communication with the listening operator to the exclusion of all other subscribers.

We will suppose that the subscriber at station 1 wishes to communicate with the listening operator. He simply depresses key Z, and, taking down his telephone, is brought into communication with the listening operatoras soon as the moving arm shall come against the actuated armature of his relay. The circuit which is thus formed may be traced from ground at the subscribers station over the two sides of the metallic circuit of the telephone-line c to the branch 6, connected through the relay and thence through the battery to ground. The armature of the relay is thus brought into the path of the moving arm and the arm closes against the same, as shown. The arm is thus brought into electrical connection with the branch 6, and the subscriber, still holding the key Z depressed and his telephone being removed from the switch,

may communicate with the listening operator. The order having been received by the listening operator, he proceeds in the usual manner to make the connection with the line wanted. hen the subscribers are through talking, the calling subscriber again depresses his key Z, thus connecting himself again with the listening operator and telling him to disconnect.

My invention admits of various modifications which would readily suggest themselves to those familiar with electrical apparatus and mechanical devices, and I therefore do not limit myself to the details of construction shown.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. A metallic circuit connecting a subscribers station with the central office, a groundingkey at the subscribers station, and a branch from said metallic circuit at the central office to ground, said branch including the coils of a relay and a source of electricity, in combination with a moving arm, whereby said arm is arrested when the relay is operated, substantially as and for the purpose specified.

2. A metallic-circuit telephone-line including one coil of a converter at the central office and in each of the different sides thereof a differentially-wonnd coil of the subscribers telephone and the inductorium thereof, a branch connection to ground from between the two oppositely-wound or diiferential coils of the telephone, said branch containing a normally-open circuit-closer, in combination with a branch to ground at the central office, said branch being connected with the said coil of the converterincluded in'said metallic circuit, and a battery and electro-magnetic circuit-closer included in said ground branch at the central oflice, substantially as and for the purpose specified.

3. The combination,with a rotating arm connected with an operators telephone, of a series of contacts arranged about said arm, each of said contacts being controlled by a different electro-magnetic device, and each of said JOHN J. CARTY.

WVitnesses:

O. G. HAWLEY, ELLA EDLER. 

